diff options
Diffstat (limited to 'drivers/gpu/drm/drm_dp_mst_topology.c')
-rw-r--r-- | drivers/gpu/drm/drm_dp_mst_topology.c | 247 |
1 files changed, 215 insertions, 32 deletions
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index e3497bc49494..88db6d7e1a36 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -3011,21 +3011,42 @@ static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr, } /** - * drm_dp_atomic_find_vcpi_slots() - Find and add vcpi slots to the state + * drm_dp_atomic_find_vcpi_slots() - Find and add VCPI slots to the state * @state: global atomic state * @mgr: MST topology manager for the port * @port: port to find vcpi slots for * @pbn: bandwidth required for the mode in PBN * - * RETURNS: - * Total slots in the atomic state assigned for this port or error + * Allocates VCPI slots to @port, replacing any previous VCPI allocations it + * may have had. Any atomic drivers which support MST must call this function + * in their &drm_encoder_helper_funcs.atomic_check() callback to change the + * current VCPI allocation for the new state, but only when + * &drm_crtc_state.mode_changed or &drm_crtc_state.connectors_changed is set + * to ensure compatibility with userspace applications that still use the + * legacy modesetting UAPI. + * + * Allocations set by this function are not checked against the bandwidth + * restraints of @mgr until the driver calls drm_dp_mst_atomic_check(). + * + * Additionally, it is OK to call this function multiple times on the same + * @port as needed. It is not OK however, to call this function and + * drm_dp_atomic_release_vcpi_slots() in the same atomic check phase. + * + * See also: + * drm_dp_atomic_release_vcpi_slots() + * drm_dp_mst_atomic_check() + * + * Returns: + * Total slots in the atomic state assigned for this port, or a negative error + * code if the port no longer exists */ int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn) { struct drm_dp_mst_topology_state *topology_state; - int req_slots; + struct drm_dp_vcpi_allocation *pos, *vcpi = NULL; + int prev_slots, req_slots, ret; topology_state = drm_atomic_get_mst_topology_state(state, mgr); if (IS_ERR(topology_state)) @@ -3034,20 +3055,54 @@ int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state, port = drm_dp_mst_topology_get_port_validated(mgr, port); if (port == NULL) return -EINVAL; - req_slots = DIV_ROUND_UP(pbn, mgr->pbn_div); - DRM_DEBUG_KMS("vcpi slots req=%d, avail=%d\n", - req_slots, topology_state->avail_slots); - if (req_slots > topology_state->avail_slots) { - drm_dp_mst_topology_put_port(port); - return -ENOSPC; + /* Find the current allocation for this port, if any */ + list_for_each_entry(pos, &topology_state->vcpis, next) { + if (pos->port == port) { + vcpi = pos; + prev_slots = vcpi->vcpi; + + /* + * This should never happen, unless the driver tries + * releasing and allocating the same VCPI allocation, + * which is an error + */ + if (WARN_ON(!prev_slots)) { + DRM_ERROR("cannot allocate and release VCPI on [MST PORT:%p] in the same state\n", + port); + return -EINVAL; + } + + break; + } } + if (!vcpi) + prev_slots = 0; + + req_slots = DIV_ROUND_UP(pbn, mgr->pbn_div); + + DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] VCPI %d -> %d\n", + port->connector->base.id, port->connector->name, + port, prev_slots, req_slots); + + /* Add the new allocation to the state */ + if (!vcpi) { + vcpi = kzalloc(sizeof(*vcpi), GFP_KERNEL); + if (!vcpi) { + ret = -ENOMEM; + goto out; + } - topology_state->avail_slots -= req_slots; - DRM_DEBUG_KMS("vcpi slots avail=%d", topology_state->avail_slots); + drm_dp_mst_get_port_malloc(port); + vcpi->port = port; + list_add(&vcpi->next, &topology_state->vcpis); + } + vcpi->vcpi = req_slots; + ret = req_slots; +out: drm_dp_mst_topology_put_port(port); - return req_slots; + return ret; } EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots); @@ -3055,31 +3110,57 @@ EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots); * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots * @state: global atomic state * @mgr: MST topology manager for the port - * @slots: number of vcpi slots to release + * @port: The port to release the VCPI slots from * - * RETURNS: - * 0 if @slots were added back to &drm_dp_mst_topology_state->avail_slots or - * negative error code + * Releases any VCPI slots that have been allocated to a port in the atomic + * state. Any atomic drivers which support MST must call this function in + * their &drm_connector_helper_funcs.atomic_check() callback when the + * connector will no longer have VCPI allocated (e.g. because it's CRTC was + * removed) when it had VCPI allocated in the previous atomic state. + * + * It is OK to call this even if @port has been removed from the system. + * Additionally, it is OK to call this function multiple times on the same + * @port as needed. It is not OK however, to call this function and + * drm_dp_atomic_find_vcpi_slots() on the same @port in a single atomic check + * phase. + * + * See also: + * drm_dp_atomic_find_vcpi_slots() + * drm_dp_mst_atomic_check() + * + * Returns: + * 0 if all slots for this port were added back to + * &drm_dp_mst_topology_state.avail_slots or negative error code */ int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr, - int slots) + struct drm_dp_mst_port *port) { struct drm_dp_mst_topology_state *topology_state; + struct drm_dp_vcpi_allocation *pos; + bool found = false; topology_state = drm_atomic_get_mst_topology_state(state, mgr); if (IS_ERR(topology_state)) return PTR_ERR(topology_state); - /* We cannot rely on port->vcpi.num_slots to update - * topology_state->avail_slots as the port may not exist if the parent - * branch device was unplugged. This should be fixed by tracking - * per-port slot allocation in drm_dp_mst_topology_state instead of - * depending on the caller to tell us how many slots to release. - */ - topology_state->avail_slots += slots; - DRM_DEBUG_KMS("vcpi slots released=%d, avail=%d\n", - slots, topology_state->avail_slots); + list_for_each_entry(pos, &topology_state->vcpis, next) { + if (pos->port == port) { + found = true; + break; + } + } + if (WARN_ON(!found)) { + DRM_ERROR("no VCPI for [MST PORT:%p] found in mst state %p\n", + port, &topology_state->base); + return -EINVAL; + } + + DRM_DEBUG_ATOMIC("[MST PORT:%p] VCPI %d -> 0\n", port, pos->vcpi); + if (pos->vcpi) { + drm_dp_mst_put_port_malloc(port); + pos->vcpi = 0; + } return 0; } @@ -3501,15 +3582,41 @@ static void drm_dp_destroy_connector_work(struct work_struct *work) static struct drm_private_state * drm_dp_mst_duplicate_state(struct drm_private_obj *obj) { - struct drm_dp_mst_topology_state *state; + struct drm_dp_mst_topology_state *state, *old_state = + to_dp_mst_topology_state(obj->state); + struct drm_dp_vcpi_allocation *pos, *vcpi; - state = kmemdup(obj->state, sizeof(*state), GFP_KERNEL); + state = kmemdup(old_state, sizeof(*state), GFP_KERNEL); if (!state) return NULL; __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base); + INIT_LIST_HEAD(&state->vcpis); + + list_for_each_entry(pos, &old_state->vcpis, next) { + /* Prune leftover freed VCPI allocations */ + if (!pos->vcpi) + continue; + + vcpi = kmemdup(pos, sizeof(*vcpi), GFP_KERNEL); + if (!vcpi) + goto fail; + + drm_dp_mst_get_port_malloc(vcpi->port); + list_add(&vcpi->next, &state->vcpis); + } + return &state->base; + +fail: + list_for_each_entry_safe(pos, vcpi, &state->vcpis, next) { + drm_dp_mst_put_port_malloc(pos->port); + kfree(pos); + } + kfree(state); + + return NULL; } static void drm_dp_mst_destroy_state(struct drm_private_obj *obj, @@ -3517,10 +3624,88 @@ static void drm_dp_mst_destroy_state(struct drm_private_obj *obj, { struct drm_dp_mst_topology_state *mst_state = to_dp_mst_topology_state(state); + struct drm_dp_vcpi_allocation *pos, *tmp; + + list_for_each_entry_safe(pos, tmp, &mst_state->vcpis, next) { + /* We only keep references to ports with non-zero VCPIs */ + if (pos->vcpi) + drm_dp_mst_put_port_malloc(pos->port); + kfree(pos); + } kfree(mst_state); } +static inline int +drm_dp_mst_atomic_check_topology_state(struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_topology_state *mst_state) +{ + struct drm_dp_vcpi_allocation *vcpi; + int avail_slots = 63; + + list_for_each_entry(vcpi, &mst_state->vcpis, next) { + /* Releasing VCPI is always OK-even if the port is gone */ + if (!vcpi->vcpi) { + DRM_DEBUG_ATOMIC("[MST PORT:%p] releases all VCPI slots\n", + vcpi->port); + continue; + } + + DRM_DEBUG_ATOMIC("[MST PORT:%p] requires %d vcpi slots\n", + vcpi->port, vcpi->vcpi); + + avail_slots -= vcpi->vcpi; + if (avail_slots < 0) { + DRM_DEBUG_ATOMIC("[MST PORT:%p] not enough VCPI slots in mst state %p (avail=%d)\n", + vcpi->port, mst_state, + avail_slots + vcpi->vcpi); + return -ENOSPC; + } + } + DRM_DEBUG_ATOMIC("[MST MGR:%p] mst state %p VCPI avail=%d used=%d\n", + mgr, mst_state, avail_slots, + 63 - avail_slots); + + return 0; +} + +/** + * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an + * atomic update is valid + * @state: Pointer to the new &struct drm_dp_mst_topology_state + * + * Checks the given topology state for an atomic update to ensure that it's + * valid. This includes checking whether there's enough bandwidth to support + * the new VCPI allocations in the atomic update. + * + * Any atomic drivers supporting DP MST must make sure to call this after + * checking the rest of their state in their + * &drm_mode_config_funcs.atomic_check() callback. + * + * See also: + * drm_dp_atomic_find_vcpi_slots() + * drm_dp_atomic_release_vcpi_slots() + * + * Returns: + * + * 0 if the new state is valid, negative error code otherwise. + */ +int drm_dp_mst_atomic_check(struct drm_atomic_state *state) +{ + struct drm_dp_mst_topology_mgr *mgr; + struct drm_dp_mst_topology_state *mst_state; + int i, ret = 0; + + for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) { + ret = drm_dp_mst_atomic_check_topology_state(mgr, mst_state); + if (ret) + break; + } + + return ret; +} +EXPORT_SYMBOL(drm_dp_mst_atomic_check); + const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = { .atomic_duplicate_state = drm_dp_mst_duplicate_state, .atomic_destroy_state = drm_dp_mst_destroy_state, @@ -3603,9 +3788,7 @@ int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr, return -ENOMEM; mst_state->mgr = mgr; - - /* max. time slots - one slot for MTP header */ - mst_state->avail_slots = 63; + INIT_LIST_HEAD(&mst_state->vcpis); drm_atomic_private_obj_init(dev, &mgr->base, &mst_state->base, |